<template>
  <div class="course">
    <Header></Header>
    <div class="main">
      <!-- 筛选条件 -->
      <div class="condition">
        <ul class="cate-list">
          <li class="title">课程分类:</li>
          <li @click="category=0" :class="category==0?'this':''">全部</li>
          <li @click="category=cate.id" :class="category==cate.id?'this':''" v-for="(cate, index) in category_list"
              :key="index">{{ cate.name }}
          </li>
        </ul>

        <div class="ordering">
          <ul>
            <li class="title">筛&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;选:</li>
            <li class="default" @click="change_order_type('id')" :class="change_order_class('id')">默认</li>
            <li class="hot" @click="change_order_type('students')" :class="change_order_class('students')">人气</li>
            <li class="price" @click="change_order_type('price')" :class="change_order_class('price')">价格</li>
          </ul>
          <p class="condition-result">共{{ total }}个课程</p>
        </div>

      </div>
      <!-- 课程列表 -->
      <div class="course-list">
        <div class="course-item" v-for="(course, index) in course_list" :key="index" >
          <div class="course-image" @click="go(course.id)">
            <img :src="course.course_img" alt="">

          </div>
          <div class="course-info">
            <h3 @click="go(course.id)">{{ course.name }}
              <span><img src="../static/image/avatar1.svg" alt="">{{ course.students }}人已加入学习</span>
            </h3>
            <p class="teather-info">huxz 百知教育教学总监
              <span>共{{
                  course.lessons
                }}课时/{{ course.lessons === course.pub_lessons ? '更新完成' : `已更新${course.pub_lessons}` }}</span>
            </p>
            <ul class="lesson-list">
              <li v-for="(lesson, key) in course.lesson_list" :key="key"><span
                  class="lesson-title">{{ key + 1 }} | 第{{ key + 1 }}节：{{ lesson.name }}</span> <span
                  class="free" v-if="lesson.free_trail">免费</span></li>
            </ul>
            <div class="pay-box">
              <span class="discount-type">{{course.discount_name}}</span>
              <span class="discount-price">￥{{course.real_price}}元</span>
              <span class="original-price">原价：{{ course.price }}元</span>
              <span class="buy-now">立即购买</span>
            </div>
          </div>
        </div>

      </div>
    </div>
    <el-pagination
        background
        :page-size="filters.size"
        :pager-count="11"
        layout="prev, pager, next, sizes"
        :page-sizes="[2,3,5,10]"
        @current-change="change_page"
        @size-change="size_change"
        :total="total">
    </el-pagination>
    <Footer></Footer>
  </div>
</template>

<script>


import Header from "@/components/Header";
import Footer from "@/components/Footer";

export default {
  name: "Course",
  data() {
    return {
      category_list: [],
      category: 0,
      course_list: [],
      total: 0,
      filters: {
        type: "id", // 排序类型默认值
        orders: "desc",   // 排序类型  desc 降序 asc升序
        page: 1, // 分页的页码
        size: 5, // 每页展示的数量
      }
    }
  },
  // 用于监听页面上的某个值发生了改变
  watch: {
    // 当分类id发生改变时则重新发起请求获取对应的课程
    category() {
      this.get_all_course();
    },
  },
  methods: {
    // 改变分页
    change_page(page) {
      this.filters.page = page;
      this.get_all_course();
    },
    // 改变每页展示的课程数量
    size_change(size) {
      this.filters.size = size;
      this.filters.page = 1;
      this.get_all_course();

    },
    // 改变排序的条件
    change_order_type(type) {
      // 通过click事件改变排序条件
      if (this.filters.type === type && this.filters.orders === "asc") {
        this.filters.orders = 'desc';
      } else if (this.filters.type === type && this.filters.orders === "desc") {
        this.filters.orders = "asc";
      }
      // 更改排序的条件
      this.filters.type = type;
      // 重新获取排序后的结果
      this.get_all_course();

    },
    // 改变样式的条件
    change_order_class(type) {
      // 更改选中的高亮效果
      if (this.filters.type === type && this.filters.orders === "asc") {
        return "this asc"
      } else if (this.filters.type === type && this.filters.orders === "desc") {
        return "this desc"
      } else {
        return ""
      }
    },
    // 获取所有课程分类
    get_all_category() {
      this.$axios.get(this.$settings.HOST + "course/category/").then(res => {
        this.category_list = res.data;
      })
    },
    // 获取所有的课程信息
    get_all_course() {
      let filters = {
        // 切换分页后的页面
        page: this.filters.page,
        size: this.filters.size,
      }
      // 完成排序
      if (this.filters.orders === "desc") {
        filters.ordering = "-" + this.filters.type;
      } else {
        filters.ordering = this.filters.type;
      }
      // 判断是否要根据分类id来查询课程
      if (this.category > 0) {
        filters.course_category = this.category;
      }

      this.$axios.get(this.$settings.HOST + "course/courses/", {
        params: filters
      }).then(res => {

        this.course_list = res.data.results;
        // 分页的总数量
        this.total = res.data.count;
        console.log(101010101,res.data);
      })
    },

    go(id) {
      this.$router.push("/detail/" + id + '/')
    },
  },
  created() {
    this.get_all_category();
    this.get_all_course()
  },
  components: {
    Header: Header,
    Footer: Footer,
  }
}
</script>


<style scoped>
.course {
  background: #f6f6f6;
}

.course .main {
  width: 1100px;
  margin: 35px auto 0;
}

.course .condition {
  margin-bottom: 35px;
  padding: 25px 30px 25px 20px;
  background: #fff;
  border-radius: 4px;
  box-shadow: 0 2px 4px 0 #f0f0f0;
}

.course .cate-list {
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
  padding-bottom: 18px;
  margin-bottom: 17px;
}

.course .cate-list::after {
  content: "";
  display: block;
  clear: both;
}

.course .cate-list li {
  float: left;
  font-size: 16px;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
  border: 1px solid transparent; /* transparent 透明 */
}

.course .cate-list .title {
  color: #888;
  margin-left: 0;
  letter-spacing: .36px;
  padding: 0;
  line-height: 28px;
}

.course .cate-list .this {
  color: #ffc210;
  border: 1px solid #ffc210 !important;
  border-radius: 30px;
}

.course .ordering::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering ul {
  float: left;
}

.course .ordering ul::after {
  content: "";
  display: block;
  clear: both;
}

.course .ordering .condition-result {
  float: right;
  font-size: 14px;
  color: #9b9b9b;
  line-height: 28px;
}

.course .ordering ul li {
  float: left;
  padding: 6px 15px;
  line-height: 16px;
  margin-left: 14px;
  position: relative;
  transition: all .3s ease;
  cursor: pointer;
  color: #4a4a4a;
}

.course .ordering .title {
  font-size: 16px;
  color: #888;
  letter-spacing: .36px;
  margin-left: 0;
  padding: 0;
  line-height: 28px;
}

.course .ordering .this {
  color: #ffc210;
}

.course .ordering .price {
  position: relative;
}

.course .ordering .price::before,
.course .ordering .price::after {
  cursor: pointer;
  content: "";
  display: block;
  width: 0px;
  height: 0px;
  border: 5px solid transparent;
  position: absolute;
  right: 0;
}

.course .ordering .price::before {
  border-bottom: 5px solid #aaa;
  margin-bottom: 2px;
  top: 2px;
}

.course .ordering .price::after {
  border-top: 5px solid #aaa;
  bottom: 2px;
}

.course .course-item:hover {
  box-shadow: 4px 6px 16px rgba(0, 0, 0, .5);
}

.course .course-item {
  width: 1050px;
  background: #fff;
  padding: 20px 30px 20px 20px;
  margin-bottom: 35px;
  border-radius: 2px;
  cursor: pointer;
  box-shadow: 2px 3px 16px rgba(0, 0, 0, .1);
  /* css3.0 过渡动画 hover 事件操作 */
  transition: all .2s ease;
}

.course .course-item::after {
  content: "";
  display: block;
  clear: both;
}

/* 顶级元素 父级元素  当前元素{} */
.course .course-item .course-image {
  float: left;
  width: 423px;
  height: 210px;
  margin-right: 30px;
}

.course .course-item .course-image img {
  width: 100%;
}

.course .course-item .course-info {
  float: left;
  width: 596px;
}

.course-item .course-info h3 {
  font-size: 26px;
  color: #333;
  font-weight: normal;
  margin-bottom: 8px;
}

.course-item .course-info h3 span {
  font-size: 14px;
  color: #9b9b9b;
  float: right;
  margin-top: 14px;
}

.course-item .course-info h3 span img {
  width: 11px;
  height: auto;
  margin-right: 7px;
}

.course-item .course-info .teather-info {
  font-size: 14px;
  color: #9b9b9b;
  margin-bottom: 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid #333;
  border-bottom-color: rgba(51, 51, 51, .05);
}

.course-item .course-info .teather-info span {
  float: right;
}

.course-item .lesson-list::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .lesson-list li {
  float: left;
  width: 44%;
  font-size: 14px;
  color: #666;
  padding-left: 22px;
  /* background: url("路径") 是否平铺 x轴位置 y轴位置 */
  background: url("../static/image/play-icon-gray.svg") no-repeat left 4px;
  margin-bottom: 15px;
}

.course-item .lesson-list li .lesson-title {
  /* 以下3句，文本内容过多，会自动隐藏，并显示省略符号 */
  text-overflow: ellipsis;
  overflow: hidden;
  white-space: nowrap;
  display: inline-block;
  max-width: 200px;
}

.course-item .lesson-list li:hover {
  background-image: url("../static/image/play-icon-yellow.svg");
  color: #ffc210;
}

.course-item .lesson-list li .free {
  width: 34px;
  height: 20px;
  color: #fd7b4d;
  vertical-align: super;
  margin-left: 10px;
  border: 1px solid #fd7b4d;
  border-radius: 2px;
  text-align: center;
  font-size: 13px;
  white-space: nowrap;
}

.course-item .lesson-list li:hover .free {
  color: #ffc210;
  border-color: #ffc210;
}

.course-item .pay-box::after {
  content: "";
  display: block;
  clear: both;
}

.course-item .pay-box .discount-type {
  padding: 6px 10px;
  font-size: 16px;
  color: #fff;
  text-align: center;
  margin-right: 8px;
  background: #fa6240;
  border: 1px solid #fa6240;
  border-radius: 10px 0 10px 0;
  float: left;
}

.course-item .pay-box .discount-price {
  font-size: 24px;
  color: #fa6240;
  float: left;
}

.course-item .pay-box .original-price {
  text-decoration: line-through;
  font-size: 14px;
  color: #9b9b9b;
  margin-left: 10px;
  float: left;
  margin-top: 10px;
}

.course-item .pay-box .buy-now {
  width: 120px;
  height: 38px;
  background: transparent;
  color: #fa6240;
  font-size: 16px;
  border: 1px solid #fd7b4d;
  border-radius: 3px;
  transition: all .2s ease-in-out;
  float: right;
  text-align: center;
  line-height: 38px;
}

.course-item .pay-box .buy-now:hover {
  color: #fff;
  background: #ffc210;
  border: 1px solid #ffc210;
}

.el-pagination {
  text-align: center;
  padding-top: 20px;
  padding-bottom: 50px;
}
</style>